Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 84-0120 - Gates C-21A - United States Air Force SPAR837 - 3.4 mi away @ 27550 ft, heading WNW at 345 mph. Spotted 17x before. [12:54:19 PM CST] #AE0175 #reg_840120 #LJ35 #SPAR837 #military #ADSB #ADSBbot